Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

E39 (1997 - 2003) The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

Last week my 1997 BMW 540i may have finally quit on me. After 2-3 weeks of a fluctuating thermostat. The radiator simply "popped", emitting a steam cloud and some coolant/water.

Now, hours before the 'pop' (at least 2 hrs prior) I put water into the reservoir which I noticed was bubbling unusually and excessively. I have owned this vehicle for 6 months now and NEVER experienced such a problem.

I am afraid I may have an underlying head gasket issue (cracked or blown), something I cannot afford to fix in this or the next lifetime.

The car still turns on as normal, also driving as such. Now, I am aware NOT to drive it, for the risk of burning it out completely.

However, my question is: Should I replace the radiator for now and work my way up to the gaskets? Or am I wasting my time buying the radiator? OR is it possible to solder the cracked area?

I must add, I questioned why the thermostat went up and down, even while driving; my car showed no signs of overheating. Therefore, many told me that the thermostat may be broken and I would simply need to replace it. All in all Ididn't think much of this.

What do I do!??!?!? I'm nervous that if I buy a new radiator that I might be wasting my money

However, my question is: Should I replace the radiator for now and work my way up to the gaskets? Or am I wasting my time buying the radiator? OR is it possible to solder the cracked area?

You're not the first person with this dilemma - so you may save yourself some time & money by reading these threads, which were compiled ahead of time for you.

- Summary advice to provide users who suspect a major engine repair due to overheating (1) (2) (3) (4) & how to test an engine for a blown head gasket, cracked heads, a warped block, stripped head bolt threads, cam seizures, contaminated bearings, coolant hydrolock, or piston, ring, or valve damage (1) (2) & what are the major factors in deciding whether to rebuild the engine, replace the engine, or sell the car (1) & a DIY for replacing the I6 M54 head gasket (1) (2) & replacing the V8 M62TU head gasket (1) & why these engines are so prone to heat-related damage in the first place (1) & welding the crack between cylinder #3 and the water jacket on the exhaust side (1) & what engine swaps are most recommended (1) (2) (3) & where to obtain a new or rebuilt head (1) replacement short block or long block (1) (2) & how to lift & remove the engine (1) & the most recent real-world results from the last 50 people faced with similar blown engine problems from which this advice came from (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50)

__________________

Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Here's my concern. The car is driveable and does now emit any smoke. I know that driving with a crack in the radiator is foolish and risky, so what could this problem actually be?

I am somewhat sure that my gaskets are "fine" and not perfect; however I was informed that something is not reguating pressure or that there is too much pressure somewhere. ( I am not savy on these things like my mother,brother and older sister).

A BMW specialist told me it might not even be a gasket problem and I should not be discouraged just yet. I was also discouraged from purchasing ANY type of sealant (of course, by many mechanics), for these will ruin my engine.

I'd replace the radiator and see if it is OK. If it is then I do the rest of the cooling system, if the radiator has gone the rest will follow!

The v8 engine runs at over boiling point, the must be pressure in the system to stop the coolant boiling. If the pressure is released then the coolant will boil and the temp will spike up. The spikes in temps you saw were probably early signs of your rad failure (it releasing the pressure through a small crack). I've seem similar issues with mine when expansion tanks have failed.

The v8 isn't as bad as the i6 for issues caused by overheating luckily and head gasket issues are prey rare. So unless you ignored the issue and ran it for a while in the red it should be fine.

Stay away from the in cooling systems sealants, they'll ruin the cooling system. I'd only use on a car that was terminal it make it last week or two more....

__________________

An e39 is like a beautiful wife, needs constant attention, lots of money, lets you down at the worse times but you’d never be without it.

+1 on replace radiator (aluminum and plastic cannot be "soldered"). They're all over the 'net for less than $150 and it may just be the only thing that's wrong at the moment, as surmised by mbell666. Of course, many will advise doing a full cooling system overhaul on a BMW of this age, unless you have records indicating that previous owner(s) did it. But simply replacing the radiator might just put you back on the road and settle your mind while you save and plan for preventative maintenance.

I am with the others. Replace the radiator and probably the expansion tank as well. If you buy from OEMbimmerparts.com, they are in San Antonio and it may come the next day! BMA auto parts from California also arrives in about 2 days with no frieght changes as well. I have been amazed by both of them.

I have coverted two of my BMW's (1999 528 i and 2001 325i) to NPG+ waterless coolant and I believe it will save your engine if you are close to overheating. mbell666 and I are both in Austin and can talk on the phone if you want to PM me.

Now, I've taken my car to D&K Auto here in Cedar Park. He's going to do the work for $390. Is that a good deal?

Next, I still have a lot of work to do on this car, but I'm afraid my patience and finances are running out with it.

Do either of y'all do any work on BMW's? If so, what are you rates? I do not mind a courtesy call or a PM. I am 6 months into ownership and experience 2 major repairs. I want to maintain this car for as long as I am able....

Send me a message of when and where I can receive some advice! I would appreciate it.

JKRIT, that's what I was afraid of...soldering is a lazy and desperate way out and into more hardship.

So, how do y'all feel about AutoHausAZ.com??? That's where I looked for a radiator, but the mechanic told me I'm risking ordering the wrong size (?). Is that possible? I felt stupid because he explained why NOT to order online simply for the fact that a) possible to order wrong size b) i would have to wait longer c) if wrong sized ordered, I'd have to send it back and start over again.

Plus, the difference in cost would only be $25, so it really wouldn't make a difference.

Pelican parts lists the radiator for $185. 3 gallons of coolant is $75 if he uses the BMW antifreeze (it's blue), but I suspect he'll use cheaper antifreeze. Probably at least $30. 3 hours of labor seems about right.

Sounds reasonable to me.

Maybe you can talk to one of the locals who posted above and see if they have anything to add. They may have some insights to mechanics in your area.

And I will connect with the local guys that offered insight about this issue.

I will definitely research Pelican Parts, for I need 3 regulators as of yesterday. May The Lord help me retain patience with this vehicle that I have fallen in love with. Will keep everyone (that cares) posted!

To answer your question above, AutoHausAZ is on my list of on-line vendors that I use. "Wrong size" is kind of a straw man argument so that the mechanic can make a few extra bucks by also selling you the radiator itself. Many independents won't let you bring your own parts anyway. I think $390 is quite reasonable for the job.

Two issues: brand of radiator and brand of coolant. There was, maybe 5-10 years ago a rash of defective radiators by one brand, but it the blogosphere seems to have quieted down on that problem now. You could search, especially on roadfly, if you care to avoid that brand. Coolant brand selection has a bit of religious fervor to it, almost like choosing oil brand/viscosity. I use the costly BMW stuff, but they are not the only company selling aluminum engines/radiators, and many people pooh-pooh the supposed additive exclusivity.